Inhalation Risk Research Articles

Quantification and probabilistic health risk assessment of benzene series compounds emitted from cooking process in restaurant kitchens

The formation of volatile organic compounds (VOCs) during cooking processes is a significant contributor to indoor pollution. Benzene, toluene, ethylbenzene, and xylene isomers (BTEX) are aromatic hydrocarbons emitted during various cooking styles, posing potential carcinogenic (CR) and non-carcinogenic health risks (n-CR). This study measured BTEX compound concentrations emitted from three common cooking methods (barbecuing, frying, and boiling) in eight restaurant kitchens located in Birjand city, South Khorasan province, Iran. Sampling was conducted near the inhalation zone for each cooking style. The associated risk from the measured concentrations was assessed probabilistically. The study results demonstrated that frying emitted the highest levels of B, X, and E, followed by barbecuing and then boiling. For T, barbecuing showed the highest emissions, followed by frying and boiling. Overall, barbecuing generated the most pollutants, followed by frying and boiling, respectively. This pattern was also reflected in the carcinogenic (CR) and non-carcinogenic (n-CR) risks associated with each cooking method. Among the kitchens examined, all showed significant n-CR, with only one kitchen indicating a possible risk level for CR. Sensitivity analysis highlighted that chemical concentrations were the primary factor influencing exposure in most kitchens, although staff behavior was also significant in other kitchens. The findings underscore the health risks posed to kitchen staff by cooking emissions. Government policies, interventions, and legislation aimed at restaurant owners, focusing on education and environmental health, are crucial steps to mitigate this problem. Staff awareness of inhalation risks associated with emissions and strategies to reduce exposure—including proper ventilation, modifying cooking styles, and using respiratory protective equipment—can significantly mitigate health risks.

Analysis and evaluation of the effect of sports on promoting health in Traditional Wushu

Nowadays, the analysis and evaluation of traditional sport in wushu promotes health in the assessment of practice has been proved to keep the body healthy, making it an excellent complement to regular exercise. Sports are a vital element of a participant’s growth and development and help in the development of psychological, physical health fitness of the body. Through involvement in sports and activities, a person learns numerous skills, experiences, and self-beliefs that are useful for developing their personality. The challenges to be facing in traditional wushu include a higher risk of headache, inhalation, spinal damage, arterial shatters, and neck injuries. This paper introduces the Data Mining technique (DM) for the effect of sports on promoting health in Traditional Wushu (TW) that assists the player in analyzing mutual information from health data. Presenting players with traditional wushu generates the pattern recognition outcomes of sports health-boosting operations. This research has been used to evaluate the influence of exercise on people’s well-being, demonstrating the nutritional benefits of athletics participation. The findings indicate that the model has been used for assessing and analyzing the accuracy that can significantly influence the promotion of the effect of human health enhancement.

Risk-oriented source apportionment and implications for mitigation strategies of VOCs in industrial parks: Insights from odor pollution and health risks

A typical industrial park in the upper reaches of the Yangtze River Economic Belt, which is 70 km from the Chongqing urban center, was used to investigate the occurrence and exposure of harmful volatile organic compounds (VOCs). An exposure risk method and a risk-oriented source apportionment approach were performed to assess the inhalation risks and apportion VOC sources, respectively. The quantitative relationships between risk factors and pollution sources were established, identifying key pathogenic and odorous VOCs. The quantitative emission reduction strategies were developed based on risk thresholds. Residents within the industrial parks face potential health risks due to pathogenic VOCs and nuisance odors, and workers in specific sectors experience two to six times higher risks than those in residential areas. Six risk sources were identified in the industrial park, ranked according to their contribution to VOC concentrations as follows: industrial sewage treatment (IST) (32.59 %), natural gas chemical industry (NGCI) (27.77 %), diesel vehicle exhaust (DVE) (12.04 %), pharmaceutical manufacturing industry (PMI) (11.14 %), chemical raw materials manufacturing (CRMM) (9.96 %), and iron and steel industry (ISI) (6.5 %). Among these, NGCI, IST, and CRMM were the top contributors to pathogenic risks, with contributions of 32.13 %, 29.71 %, and 21.71 % to non-carcinogenic risks, and 18.15 %, 19.87 %, and 27.99 % to carcinogenic risks, respectively. DVE produced significantly higher odor pollution compared to other sources, with intensities that were 3 to 10 times greater. The key pathogenic and odorous VOCs differ by source, resulting in varying control priorities for different VOC species. Reducing emissions from these six sources for 20 high-risk species (e.g., acrolein, 2-chlorotoluene, 1,2-dibromoethane, dichloromethane, and p-diethylbenzene) will simultaneously lower pathogenic and odor risks, with cumulative reduction rates ranging from 4.11 % to 93.75 %. This study provides quantitative control targets for VOCs from a health risk perspective, offering valuable guidance for developing risk management policies in industrial parks.

The effect of medical face masks on inhalation risk of bacterial bioaerosols in hospital waste decontamination station

There is insufficient research on bioaerosols in hospital waste decontamination stations. This study aimed to investigate the effect of three-layer and N95 masks in reducing the inhalation risk of bacterial bioaerosols in a waste decontamination station at a teaching hospital. Active sampling was conducted on five different days at three locations: the yard, resting room, and autoclave room in three different modes: without a mask, with a three-layer mask, and with an N95 mask. Bacterial bioaerosols passing through the masks were identified using biochemical tests and polymerase chain reaction (PCR). The median concentration and interquartile range (IQR) of bacterial bioaerosols was 217.093 (230.174) colony-forming units per cubic meter (CFU/m3), which is higher than the recommended amount by Pan American Health Organization (PAHO). The resting room had high contamination levels, with a median (IQR) of 321.9 (793.529) CFU/m3 of bacterial bioaerosols. The maximum concentration of bioaerosols was also recorded in the same room (2443.282 CFU/m3). The concentration of bacterial bioaerosols differed significantly between using a three-layer or N95 mask and not using a mask (p-value < 0.001). The non-carcinogenic risk level was acceptable in all cases, except in the resting room without a mask (Hazard Quotient (HQ) = 2.07). The predominant bacteria were Gram-positive cocci (33.98%). Micrococci (three-layer mask = 51.28%, N95 mask = 50%) and Coagulase-negative Staphylococci (three-layer mask = 30.77%, N95 mask = 31.82%) were the most abundant bioaerosols passing through the masks. The results obtained are useful for managerial decisions in hospital waste decontamination stations to reduce exposure to bioaerosols and develop useful guidelines.

Probabilistic Approach for Assessing the Occupational Risk of Olfactometric Examiners: Methodology Description and Application to Real Exposure Scenario

Human examiners, known as panelists, are exposed to an unknown occupational exposure risk while determining odor concentration (Cod) using dynamic olfactometry. In the literature, a few papers, based on a deterministic approach, have been proposed to establish this occupational risk. As a result, the purpose of this study is to develop and apply a probabilistic approach, based on the randomization of exposure parameters, for assessing and evaluating the occupational exposure risk among olfactometric examiners. In this methodology, the risk is assessed by computing the hazard index (HI) and inhalation risk (IR) to determine the non-carcinogenic and carcinogenic risks. To randomize the exposure parameters, a Monte Carlo simulation was described and then applied in real exposure scenario to establish the exposure risk in terms of probability. Therefore, a one-year survey of the working activity of olfactometric examiners of Laboratorio Olfattometrico of Politecnico di Milano university was conducted. Based on this data collection (exposure parameters and chemical data, divided according to sample categories), a randomized exposure scenario was constructed to estimate the probability and cumulative distribution function of risk parameters. Different distributions were obtained for different industrial samples categories and were compared with respect to acceptability criteria (the value of HI and IR at 95th percentile of distribution). The elaboration provided evidence that negligible non-carcinogenic and carcinogenic risks are associated with the panelists’ activity, according to an entire annual dataset. The application of probabilistic risk assessment provides a more comprehensive and effective characterization of the general exposure scenario for olfactometric examiners, surpassing the limitations of a deterministic approach. This method can be extended to future exposure scenarios and enables the selection of the most effective risk management strategies to protect the health of olfactometric examiners.

Evaluation of asbestos dispersion during laser ablation of rocks containing Naturally Occurring Asbestos (NOA)

Health risks are often overlooked when the short-term consequences are not immediately apparent. During restoration work, cleaning actions can generate particles that pose health risks to workers through inhalation. This is particularly true in the case of asbestos fibres that might be spread out from the laser cleaning of buildings or heritage artifacts made of stone, such as serpentinite and other ultramafic rocks, that have a high probability of containing asbestos (e.g., chrysotile, tremolite asbestos, actinolite asbestos). To show workers the importance of wearing proper protection to prevent health injuries, several serpentinite samples, ascertained to contain asbestos minerals by specific investigations, have been laser ablated using ad hoc modified equipment in order to collocate a HEPA filter prone to collect all dust emitted during ablation. The powder deposited on the surface of these filters after laser ablation was analyzed, by Powder X -ray Diffraction (PXRD), Transmission Electron Microscopy combined with Energy Dispersive Spectroscopy (TEM/EDS), micro-Raman spectroscopy (μ-Raman) and Fourier-transform infrared spectroscopy (FTIR/ATR). The results confirmed the presence of asbestos fibres during the laser ablation of rocks containing Naturally Occurring Asbestos (NOA), emphasizing the importance of wearing appropriate personal protective equipment (PPE) during these procedures. Noteworthy, approximately 33 % of the analyzed fibres met the WHO criteria in size for respirable fibres. Furthermore, through our experiments, we also demonstrated that using tools that integrate filters into working tools would definitively further decrease the risk of fibres inhalation to workers.

Assessment of tracheobronchial and lung dose due to radon and thoron inhalation.

The main sources of natural background radiation are radon, thoron and their progeny, which may cause health risks to humans. Keeping in mind the importance of the subject, three samples each from 10 selected residential areas, including the centre of Babylon Governorate, Iraq, and its districts, were collected. Concentration of radon and thoron was measured using solid-state track detectors (CR-39). The arithmetic means of the concentration of radon and thoron were 47.367±19.56 and 133.246±16.585 Bqm-3, respectively; these values are considered safe when compared with the upper reference level of 200-600 Bqm-3 recommended by the International Commission for Radiological Protection (ICRP). The value of the inhalation equivalent dose from radon gas discovered in these areas with rate 37.893 nSv is less than the value of the global average of 1.15 mSv. This indicates that the risks related to inhalation of radon are low as the lung dose rate (DLung), tracheobronchial region (DT-B), annual effective dose (AED) and excess lifetime cancer risk (ELCR) is (1.894 nGyh-1, 22.736 nSv, 0.236 mSvy-1 and 0.835 x10-3), respectively. While the value of the inhalation equivalent dose (IED) from thoron as effective dose to lung DLung, AED and ELCR are equal to (0.133 nSv, 0.167 mSvy-1 and 0.587 x 10-3), respectively. To conclude, the rates in the study area are less than the ICRP recommended level of 3 mSv; therefore, the studied areas are safe from the health risks of inhalation of radon and thoron.

Spatial and seasonal variations of atmospheric microplastics in high and low population density areas at the intersection of tropical and subtropical regions

There is limited information regarding spatial and seasonal variations of atmospheric microplastics (MPs) and factors influencing MPs at the intersection of tropical and subtropical regions. A one-year study was conducted at sites in a high-population-density village (HPDV) and a low-population-density village (LPDV) in Taiwan to investigate the characteristics and influencing factors of airborne MPs. The predominant shapes, sizes, and polymer compositions of MPs were fragments, 3 to 25 and 26–50 μm, and polyamide at both sites. Seasonal variation in MP morphologies was not significant. Average MP concentrations were 2.20 ± 2.97 particles/m3 and 1.92 ± 2.35 particles/m3 at the HPDV and LPDV sites, respectively, and did not differ significantly. Higher concentrations and smaller sizes of MPs were found during the summer at both sites, while the predominant wind direction was southerly or southwesterly. In samples with temperatures exceeding 25 °C, the temperature was positively associated with MP concentrations at both the HPDV and LPDV sites. These results reflect that temperature influences the variations in the concentrations and sizes of MPs at our study site. Future research should consider the adverse risks of MP inhalation during the hot season. Moreover, when sites with different population densities and levels of human activity are closed, MP concentrations will not differ significantly between these areas since airflow can transport these particles from high-population-density areas into low-population-density areas in a short time.

Airborne concentrations of bacteria and mold in Korean public-use facilities: measurement, systematic review, meta-analysis, and probabilistic human inhalation risk assessment.

Bioaerosols adversely affect human health posing risk to users of public facilities in Korea. Between October 2021 and May 2022, airborne bacteria and mold were measured in 1,243 public-use facilities across 23 categories. A systematic review and meta-analysis were performed on these and other studies from June 2004 to May 2021, and the non-carcinogenic risks to humans were assessed using Monte Carlo simulations. For bacteria, the maximum 95th percentile concentration was 584.4cfu/m3 and 1384.8cfu/m3 for mold. The heterogeneity statistic I2 was over 50% in all facilities, and for subway station bacteria, there was a significant difference according to the measurement method. The 95th percentile of hazard by population group was 8.83 × 10-2 to 3.42 × 10-1 for bacteria, and 1.31 × 10-1 to 3.55 × 10-1 for mold. The probability of a hazard quotient exceeding 1 for some population groups was derived from exposure to bacteria and mold in the air resulting from the use of all public facilities. The most powerful explanatory factor for risk was exposure time to the facility, both within (up to 0.922 for bacteria and up to 0.960 for mold) and between populations (up to 0.543 for bacteria and 0.483 for mold). This study identified populations at risk of bioaerosol exposure in Korean public-use facilities and estimated the influencing factors, highlighting the need for comprehensive improvement in bioaerosol control in public-use facilities.

The role of puff volume in vaping emissions, inhalation risks, and metabolic perturbations: a pilot study

Secondhand vaping exposure is an emerging public health concern that remains understudied. In this study, saliva and exhaled emissions from ENDS users (secondhand) and non-ENDS users (baseline) were collected, firsthand emissions were generated using an automated ENDS aerosol generation system programmed to simulate puffing topography profiles collected from ENDS users. Particulate concentrations and sizes along with volatile organic compounds were characterized. We revealed puffing topography metrics as potential mediators of firsthand and secondhand particle and chemical exposures, as well as metabolic and respiratory health outcomes. Particle deposition modeling revealed that while secondhand emissions displayed smaller deposited mass, total and pulmonary particle deposition fractions were higher than firsthand deposition levels, possibly due to smaller secondhand emission particle diameters. Lastly, untargeted metabolomic profiling of salivary biomarkers of lung injury due to firsthand ENDS exposures revealed potential early indicators of respiratory distress that may also be relevant in bystanders exposed to secondhand vaping scenarios. By leveraging system toxicology, we identified 10 metabolites, including leukotriene D4, that could potentially serve as biomarkers for ENDS use, exposure estimation, and the prediction of vaping-related disease. This study highlights characterization of vaping behavior is an important exposure component in advancing our understanding of potential health effects in ENDS users and bystanders.

Inhalation Toxicity Screening of Consumer Products Chemicals using OECD Test Guideline Data-based Machine Learning Models

This study aimed to screen the inhalation toxicity of chemicals found in consumer products such as air fresheners, fragrances, and anti-fogging agents submitted to K-REACH using machine learning models. We manually curated inhalation toxicity data based on OECD test guideline 403 (Acute inhalation), 412 (Sub-acute inhalation), and 413 (Sub-chronic inhalation) for 1709 chemicals from the OECD eChemPortal database. Machine learning models were trained using ten algorithms, along with four molecular fingerprints (MACCS, Morgan, Topo, RDKit) and molecular descriptors, achieving F1 scores ranging from 51 % to 91 % in test dataset. Leveraging the high-performing models, we conducted a virtual screening of chemicals, initially applying them to data-rich chemicals generally used in occupational settings to determine the prediction uncertainty. Results showed high sensitivity (75 %) but low specificity (23 %), suggesting that our models can contribute to conservative screening of chemicals. Subsequently, we applied the models to consumer product chemicals, identifying 79 as of high concern. Most of the prioritized chemicals lacked GHS classifications related to inhalation toxicity, even though they were predicted to be used in many consumer products. This study highlights a potential regulatory blind spot concerning the inhalation risk of consumer product chemicals while also indicating the potential of artificial intelligence (AI) models to aid in prioritizing chemicals at the screening level.

Effectiveness of respiratory protective equipment in reducing inhalation and contact exposure risks of dental workers during ultrasonic scaling

The high-concentration droplets produced from ultrasonic scaling treatments may carry many pathogens. The close contact between dental workers and patients significantly amplifies their exposure risk to these droplets. Although various types of respiratory protective equipment (RPE) are utilized by dental workers during treatments, their effectiveness in reducing the risks associated with inhalation and contact exposure remains uncertain. In this study, computational fluid dynamics technology was employed to investigate the impact of RPE type, surgery duration, air changes per hour (ACH), and air distribution on the risks related to inhalation and deposition exposure. The results revealed that wearing masks considerably reduced the risk of inhalation exposure for dental workers, with a decrease in inhalation fractions from 25.3 ppm (without RPE) to 1.3–4.5 ppm (with RPE). Combining blue surgical masks and face shields decreased the risk of inhalation fraction by 5% compared to wearing no RPE. Notably, there was over 60% of spray droplets landed on the patient's head; however, only approximately 5%, 6%, 8%, and 3% were deposited on the patient's body, doctor's body, floor, and dental chair, respectively. Increasing ventilation from 3 to 9 ACH decreased dental workers' inhalation fraction by 9.8 ppm. Type III (with the inlet and outlet at opposite walls) decreased the suspension fraction by 4.3% compared with Type II (with the inlet and outlet at the same wall) while achieving a near-zero inhalation fraction of dental workers. These findings offer valuable insights for mitigating cross-infection risks between dental workers and patients in dental clinics.

Effects of recirculation and air change per hour on COVID-19 transmission in indoor settings: A CFD study with varying HVAC parameters

COVID-19 has already claimed over 7 million lives and has infected over 775 million people globally [1]. SARS-CoV-2, the virus that causes Covid-19, spreads primarily through droplets from infected people's airways, rendering Heating, Ventilation, and Air Conditioning (HVAC) systems critical in controlling infection risk levels in the indoor environment. To understand the dynamics of exhaled droplets and aerosols and the percentage of particles that are inhaled, escaped, recirculated, or trapped on different surfaces for a variety of environmental settings, we have presented our findings from the Computational Fluid Dynamics (CFD) modeling to investigate the impact of changing HVAC parameters in this paper. When combined with the spatial and temporal distribution of droplets, this method can be used to assess the potential risk and strengthen resilience. This finding demonstrates the viability and usefulness of CFD for modeling the distribution and dynamics of droplets and aerosols in confined environments. Our study demonstrates that raising the Air Change per Hour (ACH) from 2 to 8 reduces the risk of particle inhalation by nearly 70 %. Additionally, limiting the amount of air recirculation or increasing the amount of fresh air helps to reduce the number of airborne particles in an indoor space. To reduce the potential for respiratory droplet-related transmission and to provide relevant recommendations to the appropriate authority, the same computational approach could be applied to a wide range of ventilated indoor environments such as public buses, restaurants, exhibitions, and theaters.

Volatile Organic Compounds on Rhodes Island, Greece: Implications for Outdoor and Indoor Human Exposure.

Volatile organic compounds (VOC) are considered a class of pollutants with a significant presence in indoor and outdoor air and serious health effects. The aim of this study was to measure and evaluate the levels of outdoor and indoor VOCs at selected sites on Rhodes Island, Greece, during the cold and warm periods of 2023. Spatial and seasonal variations were evaluated; moreover, cancer and non-cancer inhalation risks were assessed. For this purpose, simultaneous indoor-outdoor air sampling was carried out on the island of Rhodes. VOCs were determined by Thermal Desorption-Gas Chromatography/Mass Spectroscopy (TD-GC/MS). Fifty-six VOCs with frequencies ≥ 50% were further considered. VOC concentrations (∑56VOCs) at all sites were found to be higher in the warm period. In the warm and cold sampling periods, the highest concentrations were found at the port of Rhodes City, while total VOC concentrations were dominated by alkanes. The Positive Matrix Factorization (PMF) model was applied to identify the VOC emission sources. Non-cancer and cancer risks for adults were within the safe levels.

Severity of Inhalation Injury and Risk of Nosocomial Pneumonia: A Retrospective Cohort Study

BackgroundThe impact of inhalation injury on risk of nosocomial pneumonia, an important complication in burn patients, is not well established. Research QuestionIs more severe inhalation injury associated with increased risk of nosocomial pneumonia? Study Design and MethodsWe performed a retrospective cohort study of patients with suspected inhalation injury admitted to a regional burn center from 2011 to 2022 who underwent diagnostic bronchoscopy within 48 hours of admission. We estimated the association of high-grade inhalation injury (abbreviated injury score [AIS] 3-4) versus low-grade inhalation injury (AIS 1-2) with nosocomial pneumonia (NP) adjusted for age, burn size, and comorbid obstructive lung disease. Death and hospital discharge were considered competing risks. ResultsOf the 245 patients analyzed, 51 (21%) had high-grade injury, 180 (73%) had low-grade injury, and 14 (6%) had no inhalation injury. Among the 236 patients hospitalized for >48 hours, NP occurred in 24/50 (48%) patients in the high-grade group, 54/172 (31%) in the low-grade group, and 2/14 (14%) in the no inhalation injury group. High-grade (vs low-grade) inhalation injury was associated with higher hazard of NP in both the proportional cause-specific hazard model (CSHR 2.04; 95% CI, 1.26-3.30; p=0.004) and Fine-Gray subdistribution hazards model (SHR for NP, 2.24; 95% CI, 1.38-3.64; p=0.001). InterpretationAmong patients with inhalation injury, more severe injury was associated with higher hazard of NP in competing risk analysis. Additional research is needed to investigate mechanisms that may explain the relationship between inhalation injury and NP and to identify more effective prevention strategies.

IMPACT OF THE SPACE INDUSTRY ON CANCER INCIDENCE IN THE POPULATION OF KAZAKHSTAN: A LITERATURE REVIEW

Relevance: Resolving the impact of the space industry on cancer incidence comes down to assessing and preventing the environmental risks caused by the Earth’s surface contamination with space debris and rocket fuel combustion waste. Components of liquid rocket fuel, like unsymmetrical dimethylhydrazine (UDMH) and others, have proven general toxic, carcinogenic, teratogenic, and mutagenic properties. The research available in the world uses calculations of the individual inhalation and oral carcinogenic risk of the effect of UDMH and its derivative N-nitrosodimethylamine on public health. Cancer incidence is an indicator of the specific influence of carcinogenic and co-carcinogenic environmental factors on public health. The Ulytau region is particularly interesting since separating parts of launch vehicles usually fall there, and sub-route areas are located there. From 2020 to 2022, the Karaganda region, including districts and cities that later became part of the Ulytau region, ranked 5th in cancer incidence in Kazakhstan. The study aimed to analyze published data on cancer incidence among the population of the Ulytau region living near the areas where the separated parts of launch vehicles fell and determine the direction of further research. Methods: A literature search in the PubMed database and archives of Kazakhstani scientific editions revealed 35 literature sources that met the search criteria. The analysis included 29 scientific publications examining the health status of a population exposed to rocket and space activities, including reference materials. Data on morbidity and mortality from neoplasms in the population of several districts of the Karaganda region was analyzed. Results: Research data analysis showed conflicting conclusions regarding the influence of rocket fuel components on the health of the population living in the zones of influence of the rocket and space activities. Some researchers found increased morbidity and mortality in the population, but others did not reveal statistically significant differences with control groups. An analysis of data on the mortality of the population living near the regular and emergency areas of fall of separating parts of launch vehicles in the Karaganda region showed an increased mortality rate for some nosologies. Conclusion: No studies have compared the cancer incidence in the Ulytau region’s population living in areas adjacent to the fall areas of separating parts of launch vehicles with the control areas.

Indoor/Outdoor airborne microbiome characteristics in residential areas across four seasons and its indoor purification

Bioaerosols are more likely to accumulate in the residential environment, and long-term inhalation may lead to a variety of diseases and allergies. Here, we studied the distribution, influencing factors and diffusion characteristics of indoor and outdoor microbiota pollution in six residential buildings in Guangzhou, southern China over a period of one year. The results showed that the particle sizes of bioaerosol were mainly in the range of inhalable particle size (<4.7 μm) with a small difference among four seasons (74.61 % ± 2.17 %). The microbial communities showed obvious seasonal differences with high abundance in summer, but no obvious geographical differences. Among them, the bacteria were more abundant than the fungi. The dominant microbes in indoor and outdoor environments were similar, with Anoxybacillu, Brevibacillus and Acinetobacter as the dominant bacteria, and Cladosporium, Penicillium and Alternaria as the dominant fungi. The airborne microbiomes were more sensitive to temperature and particulate matter (PM2.5, PM10) concentrations. Based on the Sloan neutral model, bacteria were more prone to random diffusion than fungi, and the airborne microbiome can be randomly distributed in indoor and outdoor environments and between the two environments in each season. Bioaerosol in indoor was mainly from outdoor. The health risk evaluation showed that the indoor inhalation risks were higher than those outdoor. The air purifier had a better removal efficiency on 1.1–4.7 μm microorganisms, and the removal efficiency on Gram-negative bacteria was better than that on Gram-positive bacteria. This study is of great significance for the risk assessment and control of residential indoor bioaerosol exposure.

A Potential Inhalation Risk to Daily Commuter: Mobile Monitoring of Black Carbon during Journey in Traffic Emissions

A Potential Inhalation Risk to Daily Commuter: Mobile Monitoring of Black Carbon during Journey in Traffic Emissions

Next generation risk assessment of biocides (PHMG-p and CMIT/MIT)-induced pulmonary fibrosis using adverse outcome pathway-based transcriptome analysis

Next-generation risk assessment (NGRA) has emerged as a promising alternative to non-animal studies owing to the increasing demand for the risk assessment of inhaled toxicants. In this study, NGRA was used to assess the inhalation risks of two biocides commonly used as humidifier disinfectants: polyhexamethylene guanidine phosphate (PHMG-p) and chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT). Human bronchial epithelial cell transcriptomic data were processed based on adverse outcome pathways and used to establish transcriptome-based points of departure (tPODs) for each biocide. tPOD values were 0.00500–0.0510 μg/cm2 and 0.0342–0.0544 μg/cm2 for PHMG-p and CMIT/MIT, respectively. tPODs may provide predictive power comparable to that of traditional animal-based PODs (aPODs). The tPOD-based NGRA determined that both PHMG-p and CMIT/MIT present a high inhalation risk. Moreover, the identified PHMG-p posed a higher risk than CMIT/MIT, and children were identified as more susceptible population compared to adults. This finding is consistent with observations from actual exposure events. Our findings suggest that NGRA with transcriptomics offers a reliable approach for risk assessment of specific humidifier disinfectant biocides, while acknowledging the limitations of current models and in vitro systems, particularly regarding uncertainties in pharmacokinetics (PK) and pharmacodynamics (PD).

Dry deposition fluxes and inhalation risks of toxic elements in total suspended particles in the Bohai Rim region: Long-term trends and potential sources

Long-term changes in dry deposition fluxes (DDF) and health risks for toxic elements (TE) in total suspended particles (TSP) in the Bohai Rim region are important for assessing control effects of pollution sources. Thus, we investigated the trends in DDF and concentrations for TSP and TE and health risks of TE in eight cities in the region from 2011–2020. TSP concentration and DDF showed general downward trends. Compared to the before Clear Air Action Plan (BCAAP, 2011–2012) period, concentration and DDF of TE over the Clear Air Action Plan (CAAP, 2013–2017) period substantially decreased, with the highest decrease rates in Zn, Cd, and Cr. During the study period, non-carcinogenic (HI) and total carcinogenic (TCR) risks for children and adults were 0.09 and 0.04, and 1.54 × 10−5 and 2.65 × 10−5, respectively, with Cr6+ and As being dominant contributors. Compared to the BCAAP period, HI and TCR over the CAAP period decreased by 36.8 % and 32.4 %, respectively. However, their risks increased over the Blue Sky Protection Campaign (BSPC, 2018–2020) period. Potential source contribution function suggested substantial changes in potential risk areas over different control periods, with the BSPC primarily being on land and the Yellow Sea.